Petcock seating

[angrypants]

Hi guys tried to search this but no luck - I've pretty much completed the basics requirements as per the list without the need to post and ask and I thank you all for sharing your knowledge ! I really do, this is an amazing resource !!
eg fork seals valves points timing wheel align lights / wiring ,rebuild calipers masters , rebuilt the petcock , changed the bearings, fully refurbed and dipped the cabs boot and oring s, weld plates on the underside exhaust and lastly sealing the tank all using the search function- and I knew nothing 12 months ago !! but I'm stuck here

where your petcock bolts in ... what is under it ? paint or do you clear the paint so the gasket thingo between the two bolts is pressing 100% against bare metal ? Looks like the Po has the tank resprayed and paint is all the way to the hole ... and looks like it's sufffered from exposure to the fuel .. bubbled / rippled a bit

do i I take it back to metal or just bolt it back on ?

Thanks !
grant

[roeme]

Simply bolting it back on should be fine. Though I had a similiar problem as you; paint flaked around the petcock area. As I was cleaning, paint came partially off. I took the loose, flaky parts off with a veeeery cautious & soft application of 00-grade steel wool. Afterwards, sealing area was partially blank metal, partially paint. Let the filled tank sit over night with some bucket underneath - didn't leak, hasn't since.

[cowboyup3371]

Maybe clean it up a bit then bolt right in

[angrypants]

Thanks I'll clean it up and test for a few hours before putting it back on the bike

[Mr.humbucker]

If when I find a slow leak I tend to tighten it up a tad first as I've found when it got cold it leaked. When it persisted I cleaned up and removed most of the paint in the immediate area. I also used dowty washers on the bolts to minimize the risk of fuel leaking from there ... seems to help.

[bwringer]

Stock, they're just on top of the paint.

Repainted, or if the stock paint has lifted, you'll want to carefully clean things up to bare metal. You need a smooth, sound sealing surface for the o-ring. (And always use a new o-ring, too.)


And new sealing washers around the bolts are a MUST; these bolt holes enter the tank. The stock sealing washers are similar to dowty washers and are very cheap, so you might as well grab some when order the o-ring.

I've successfully used 1/4" black nylon washers from the hardware store many times over many years.

[John Park]

I've successfully used 1/4" black nylon washers from the hardware store many times over many years.

Thanks muchly for the tip. I've always had my doubts about Dowty washers.

[Grimly]

Thanks muchly for the tip. I've always had my doubts about Dowty washers.

I've always had my doubts about the prices some rip-off artists charge for Dowty washers. That, and being in the sticks means that such hardware stockists that might have them at a reasonable price are too far away, and the postage cost just isn't feasible for a pair of washers. It offends my Scottish tightness gene.

One of my petcocks is held on with two plain flat washers under the heads of the bolts, each surface being sealed with Hylomar and then tightened after a short while. Never a trace of leakage from that in several years.

[Mr.humbucker]

Prior to getting a few dowty washers I improvised and put a couple of spare o rings on the bolts and cranked them on at a reasonable torque ... worked great.

[Gorminrider]

Wondering what a "dowty washer" is! Dowty Washers.jpg

ahh, these things, eh? Look useful alright. I'll normally just punch a washer from gasket paper in a pinch which works ok